Telephone receiver



Patented Get. 26, 1926.

Lanai NATHANIEI BALDWIN, 0F EAST lud-LILI( CREEK, UTAH.

TELEPHONE RECEIVER.

pplication led December 5, 1924. Serial o. 754,183.

The present invention appertains to tele phone receivers'and is particularly an improvenient over my former Patents No. 957.403. issued May 10, 1910, and No. 1,153,503, issued Sept. 14, 1915.'

The objects are to further simplify the construction and to improve the efiiciency by providing a magnet of `greater capacity.

rThe invention is illustrated in the accompanyingl drawing wherein Fig. 1 is an ele vation of the instrument having the bottom of the shell cut away. Fig. i2 is an elevation of the instrument at right angles to that shown in Fig. 1 and showing the shell and earpiece in section along the line AB of Fig.

1. and Eig. 3 is a metrical Section along the line CD :if Fig. 1, showing the arrangement of the vurlous working parts.

Inthc figures of the drawing numeral 1 ,designates the shell or casing which has the rim of the annular hase plate 2 seated against its edge. To this base plate the horse shoe magnet 3 is secizred b v mea-ns of solder, screws, or other 'means not. shown.

The opposite parallel surfaces of the poles of the magnet 3 are provided with U-shaped polepieces 4 and 5 which are secured to the magnet by means of screws or otherwise. The limbs of these polepieces are partly cut away and arranged so that the remaining portions overlap each other as shown in Fig. 1, leaving a narrow space between their edges.

Between the limbs ot the polepieces 4 and S the spool G is located and held firmly and accurateiv in proper position, being surrounded by the said polepieces and the projecting edges 7, 7 and 8, 8 which are formed Aupon them.

Vithin the spool 6 the armature 9 is held iu position by the liexible fulcrum Wires 10, lo aud its ends project on either side 1nidway between the edges of the limbs of the po'epieces 4 and 5.

A1 one end the armature 9 is connected by a bolt 1l. Washer l2 and nut 13 to the center oi the diaphragm 14 which is seated upon the rim ot the hase plate 2 and clamped in position by the earpiece 15. At the other end the armature 9 is acted upon by a spring 16 one end of which fits into a socket in the armature 9 and the other end tits into a socket in the end of the adjusting screw 17. By means of this adjusting screw 17 which is tapped into the insert 18 set in the polepieee and the nut 13 the armature 9 can beset in the proper positionbetween the polepieces and the tension of the diaphragm can be adjusted.

Upon the base plate 2 and Within the magnet?) a block of insulating material 19 is se cured by a screw 20, and screws 21, 2l are tapped yinto this block 19. The terminals ot the winding upon the spool 6 are soldered to washers 22, 22 and the cord tips S23, 23 are held in contact with these Washers b v the screws 21, 21.

I claim:

1. A telephone receiver com l rising a spool containingthe actuating Winciinff, an armature ulcrumed Within said spoobl, U-shaped polepieces inclosing said spool and acting upon sai'l armature, projecting edges upon said polepieces to hold said spool in proper position, a magnet contacting with said polepieces, aud a diaphragm actuated by said armature.

2. A telephone receiver comprising a spool containing the actuating Winding, an armature tulcrumed Within said spool, U-shaped polepicces inclosing said spool and acting upon said armature, projecting edges upon said polepieces to hold said spool in. proper position, a magnet contacting With said polepieces, a diaphragm. and means to transmit RESSED the movements of said armature to said diaphrag-m.

3. A telephone receiver comprising ahorse- A shoe magnet, U-shaped polepeces attached to the poles of said magnet with the limbs of one polepiece overlapping the limbs ofthe other. .as-pool containing the actuating Winding' inelosed by said polepieces, projecting edges formed upon sald polepieces to hold said-spool in proper position, an armature tulcrumed within said spool and acted upon by the overlapping limbs of said polepieces, and a diaphragm actuated by said armature.

4, A telephone receiver comprising a horeshoe magnet, U-shaped polepieces attached to thejpoiljes of said magnet with the limbs of onePQiepiece overlapping the limbs of the other, a spool containing the actuating winding ip'closed by said polepieces,

proj exiting,r edges formed upon said polepieces to hold said spool in proper position, an ar mature fulcrumed Within said spool and act-- ed upon by the overlapping limbs -of said polepieces, a diaphragm, and means to trans mit the movements of said armature to said diaphragm.

' NATHANlEL 

